下腔静脉直径变化对高PEEP休克患者容量反应性的预测价值

Value of Changes of Inferior Vena Cava Diameter to Predict Fluid Responsiveness of Shock Patients with High PEEP

目的评估床边超声测量下腔静脉直径变化对于高呼气末正压(positive end-expiratory pressure,PEEP)休克患者容量反应性(fluid responsiveness,FR)的预测价值。方法前瞻性选取2016年6月至2018年12月在武汉协和医院ICU住院治疗行机械通气的休克无自主呼吸患者50例,最终40例入选。调整呼吸机参数(容量控制模式,潮气量6~8 mL/kg,PEEP调至15 cmH2O,若患者正在使用高PEEP进行治疗则不调节),稳定0.5 h后置入经食道超声探头记录心输出量(cardiac output,CO)。应用床旁超声测量3个完整呼吸周期的下腔静脉最大直径、最小直径,并计算最大直径平均值(Dmax)、最小直径平均值(Dmin)及其差值(ΔD)。测量后选用羟乙基淀粉130/0.4氯化钠注射液(7 mL/kg),30 min内输注完毕。分别于补液试验前后记录患者血流动力学各指标。以补液前后CO增加量(ΔCO)≥15%为标准,将患者分为有反应组(R组)和无反应组(NR组),比较两组一般情况、补液前后血流动力学指标及下腔静脉直径变化,评估各指标预测FR的价值,并计算出最佳阈值。结果 R组与NR组相比,补液前下腔静脉直径塌陷率(ΔIVC1)、下腔静脉直径变异率(ΔIVC2)均明显增大,其差异有统计学意义(均P<0.05);应用ROC曲线计算出ΔIVC1、ΔIVC2最佳阈值分别为13.5%、12.7%。结论ΔIVC1、ΔIVC2可以作为补液前预测FR的指标,分别大于13.5%、12.7%时预测价值较高。

Objective To evaluate value of changes in the inferior vena cava diameters of shock patients with high positive end expiratory pressure(PEEP)to predict fluid responsiveness(FR).Methods We chose 50 shock patients without spontaneous breathing under mechanical ventilation from the intensive care unit(ICU)of Wuhan Union Hospital prospectively from June 2016 to December 2018,and four fifths of the patients were included in the study.We adjusted the parameters of ventilator(applying capacity control mode,tidal volume of 6-8 mL/kg,PEEP of 15 cmH2O,and if the patient was under high PEEP treatment,we kept the ventilator parameters as the same during the test).Half an hour later,the transesophageal ultrasound probe was put into the esophagus to show us the cardiac output(CO).We used bedside ultrasonography to measure maximal diameter and the minimum diameter of the inferior vena cava in three complete breathing cycles,then we could get the mean maximal diameter(Dmax),the mean minimum diameter(Dmin)and the mean difference(ΔD)between them.After measuring,0.6% HES 130/0.4 was infused in 30 min at a dose of 7 mL/kg.We recorded the hemodynamics parameters before and after the test.The patients were divided into two groups according to the changes in cardiac output(ΔCO).Those with ΔCO≥15% belonged to responders(group R),and the others were nonresponders(group NR).We compared the general information,the blood gas index,hemodynamics and inferior vena cava diameter changes before and after fluid challenge,evaluated the value of the index on predicting FR and calculated the optimal thresholds.Results The expansion of inferior vena cava diameter(ΔIVC1)and the variation inferior vena cava diameter(ΔIVC2) of the two groups were increased,and the differences were statistically significant(P<0.05).The optimal thresholds of ΔIVC1 and ΔIVC2 were 13.5% and 12.7% using the receiver operating characteristic curve(ROC curve).Conclusion ΔIVC1 and ΔIVC2 can be used as good predictors in FR of shock patients with high PEEP,and the predictive value could be higher when they are more than 13.5% and 12.7%,respectively.